1. Field of the Invention
The invention relates to a bumper assembly for an automotive vehicle and, more particularly, to a retainer and fastener for attaching a resin panel or bumper to the body of the vehicle.
2. Description of the Related Art
Modern automotive vehicles utilize resin bumper covers and panels. Bumper covers serve a dual function of defining an outer appearance of the vehicle and absorbing bumps and impacts experienced at the front and rear ends of the vehicle. It is known to provide integrally formed ribs to strengthen a resin bumper or panel to better withstand the bumps and impacts. Integrally formed ribs, however, present the potential for unsightly sink marks or lines to be formed along the outer surface of the bumper. The sink marks or lines usually result from uneven cooling between the main substrate or wall of the bumper and the ribs. Guidelines for designing ribs that do not result in sink lines are well known in the art. These guidelines in general limit the radius defined between the ribs and the inner surface of the bumper wall and also the size, i.e. width and depth, of the ribs based on the thickness of the main wall of the bumper. Similar guidelines are applied to the design of integrally formed fasteners or bosses for holding fasteners on a resin panel.
Thus, it remains desirable to provide a way of reinforcing a resin panel or bumper, while minimizing or eliminating the possibility of forming undesirable sink lines alone the outer surface of the panel or bumper.